The goal of this project is to fill the key gap in this precompetitive space by providing appropriate structurally-similar inactive control compounds, which have zero or dramatically reduced activity against the specific target, to complement the high-quality probes donated by the pharmaceutical partners. The team from the NCATS Division of Preclinical Innovation has embarked on efforts to provide inactive control compounds for several targets in partnership with the SGC and the private partners donating said probes. During the reporting period, the team has selected several candidate inactive controls and has evaluated synthetic strategies to produce said controls. Three molecules are currently being produced at an approximately 100 mg scale. When ready, these samples will be tested for identity and purity, and provided to SGC for inclusion into a publicly-available set of probes and controls.